Envelope sealing machine



Feb. 5, 1946. E. E. GRAY ENVELOPE SEALING MACHINE Filed Ap ilzs, 1941 Patented Feb. 5, 1945 UNITED STATES PATENT ()FFICE ENVELOPE SEALING MACHINE El'm'i E. Gray, san es", Mass.

Application April 25, 1941, Serial No. 390.313

, 3 Claims.

The present invention relates generally to envelope sealing machines, more particularly to those parts of envelope sealing machines which effectuate the sealings of the envelopes, and most specifically to those parts of envelope sealing machines which position for moistening, and effect the moistening of, the flaps of the envelopes prior to the operation of sealing.

The principal object of the present invention is .to provide improved moistening mechanism which will effectively and adequately moisten the flaps of envelopes made of stocks of various thick nesses and degrees of stiffness, so that envelopes of various thicknesses and degrees of stiffness can be efiiciently ealed by the use of envelope sealing machines provided with such improved moistening mechanism.

Another object of the present invention is to provide improved moistening mechanism which will effectively and adequately moisten the flaps of envelopes, by maintaining the gum-bearing surfaces of the flaps of the envelopes in sliding frictional contact with the moistening mediiim, thus starting the gum and insuring the penetration of the gum by the water derived from the moistening medium.

Another object of the present invention is to provide improved moistening mechanism which will effectively and adequately moisten the flaps of envelopes, by maintaining the gum-bearing surfaces of the flaps of the envelopes in sliding frictional contact with the moistening medium under pressures that are substantially propor tional to the degrees of stiffness of the flaps of the envelopes.

Another object of the present invention is to provide improved moistening mechanism which will effectivel and adequately moisten the flaps of envelopes, by supplying moisture to the flaps of the envelopes in amounts sufficient but not excessive for the purpose of moistening the flaps of the envelopes.

Another object of the present invention is to provide improved moistening mechanism which will effectively and adequately moisten the flaps of envelopes while controlling the amounts of moisture supplied to the flaps of the envelopes.

Another object of the present invention is to provide improved moistening mechanism which will effectively and adequately moisten the anyone skilled in the art, when consideration is given to the following description of the present invention, together with the accompanying drawing thereof which forms a part of the specification, wherein:

Fig. 1 is a lateral view of an envelope sealing machine with a portion thereof cut away to show an end view of the improved moistening mecha msm.

Fig. 2 is a front end view of an envelope sealing machine showing a lateral View of the improved moistening mechanism.

Fig. 3 is a plan view of an envelope sealing machine showing a plan view of the improved moistening mechanism mounted thereon.

Fig. 4 is a plan View of an envelope sealing machine showing a plan view of the improved moistening nieehanismmounted thereon and an en velope with its flap passing through the improved moistening mechanism and thereby undergoing the moistening process.

Fig. 5 is'an end view' of the improved moistening mechanism, in part, detached from the envelope sealing machine, and a I Fig. 6 is an elevational view, doubly erpem dicular to the element [2 in Fig. 5, of a portion of the improved moistening mechanism, as shown in Fig. 5', showing the moistening medium and the pressure members for maintaining the gum bearing' surfaces of the flaps of the envelopes in sliding frictional contact with the moistening medium under pressures that are substantially proportional to the stiifnesses of the flaps of the envelopes.

A cursory examination of Fig. 1 discloses the facts that the improved moistening mechanism comprises a plate I, secured to anenvelope seal-' ing machine at slight inclinations to the horizontal plane along the longitudinal and latitudinal axes of the envelope sealing machine by means of the bracket 2', and provided with a conduit for liquid 3-, girdled by a rubber stopper 4 and surmounted by an inverted container for liquid 5,

and with ancillary devices for effectively and adequately moistening the flaps of envelopes. A more searching examination of the drawings, and of Figs. 1', 2', 5, and 6, in particular, discloses the facts that the left front portion of the plate I, shown in Figs, 1 and 5, is disposed at such an an-- gle to the main portionof the plate I as to comperisate for the tilt of the plate I to the horizontal plane, so that its edge is substantially horizontal, as is shown at 6 in Figs. 1- and 5; that the plate I is provided with a slot 1 with an upturned up a; venting into an underlying basin 9 receiving liquid from the inverted container for liquid through the conduit for liquid 3; that the ends and the edges of the moistening medium ID, a flat body of absorbent material bent upwardly into a curved surface, repose in the underlying basin 9, while the central portion of the moistening medium In is disposed over a wire support I I, which, secured at one of its ends to the plate 1 near the conduit for liquid 3, runs the length of the slot 1, and thus maintains the moistening medium It? in position for the moistening Of'the flaps of envelopes; and finally, that the plate I carries a bracket I2, to which are secured, by means of the thumb-screw 13, the integrated pressure members 14 and [5, for maintaining the gum-bearing surfaces of the flaps of envelopes in sliding frictional contact with the moistening medium in under pressures that are substantially proportional to the stiifnesses of the flaps of the envelopes. For, of the pressure members l4 and I5, I4 is substantiall rigid, is, in length, the length of the moistening medium l0, and is, in cross section, a right angle with its apex greatly rounded, while i5 is a suitably flexible member which has the conformation shown in Figs. 1-6 and which overhangs the moistening medium ID, as is particularly well shown in Fig. 6, so that its outside edge overlaps the upturned lip 8 of the slot I; the flexible pressure member I5 is displaceable laterally in a vertical plane, and, as it is displaced, it exerts, for small displacements, restitutive forces substantially proportional to the displacements. The sealings of the efiectively and adequately moistened flaps of the envelopes to the bodies of the envelopes are erformed by the usual sealing mechanism comprising the flexible metal strip [6, stiffened by the reinforcing metal strip I1, and the roller l8, upon which the end of the flexible metal strip l6 rests and exerts pressure, between which the flaps and bodies of the envelopes are passed as they leave the improved moistening mechanism.

The operation of the improved moistening mechanism is characterized by great simplicity: the envelope, as it enters the improved moistening mechanism, has its flap separated from its body'and lifted by the left front edge of the plate I, and then the flap is carried beneath the rigid pressure member 14, over the moistening medium ill, when the gum-bearing surface of the flapis brought into sliding frictional contact with the moistening medium [0, and under the flexible pressure member l5, when the envelope emerges from the improved moistening mechanism to pass into the sealing mechanism.

If, with the aid of Fig. 6, the moistening operation is examined in greater detail, it will readily be realized that the flap of the envelope, as it is carried beneath the rigid pressure member I4 and up over the ridge of the moistening medium i0, is bent upwardly to a slight degree; and, as the envelope travels forwardly, from left to right in Fig. 6, the edge of the flap of the envelope comes into contact with the under surface of the flexible pressure member l5 and "slides upon that surface, and, in so doing, lifts the flexible pressure 1 member l5 upwardly, and finally passes out from will be bent over the ridge of the moistening medium l0 into an arc, and the radius of curvature of this are will be substantially proportional to the stiffness of the flap of the envelope, and the upward displacement of the flexible pressure member 15 from its position of equilibrium will be substantially proportional to the radius of curvature of this arc. Since the stifier is the flap of the envelope, the greater is the upward displacement of the flexible pressure member [5 from its position of equilibrium, the stiffer is the flap of the envelope, the greater is the lateral pressure exerted upon it by the flexible pressure member [5. In this manner, the improved moistening mechanism effectively and adequately moistens. the flaps of envelopes of any degree of stiffness. And since the flaps of the envelopes make sliding frictional contact, under pressure, with the moistening medium Hl over a superficial area, the cross section of which is the are above described, in part, it is obvious that such sliding frictional contact, under pressure, distributed over a surface, effectively supplies moisture to the flaps of the envelopes in amounts suflicient but not excessive for the purpose of moistening the flaps of the envelopes, and controls the amounts and the volumes of the moisture so supplied, thereby insuring the penetration of the gum on the flaps of the envelopes by the water derived from the moistening medium 10 and thus effectually starting the gum on the flaps of the envelopes.

While one construction has been illustrated and described as the preferred embodiment of the present invention, it is to be understood that this construction is capable of variation and modification without departing from the spirit of the present invention. Therefore, the present invention is not to be regarded as limited to this precise embodiment thereof, illustrated and described in the specification, nor to any other specific embodiment thereof, but is to be understood to be limited only to the scopes of the appended claims.

Having fully disclosed the present invention, what I claim is:

1. In an envelope sealing machine, moistening mechanism comprising, in combination, a fixed rigid pressure member, a fixed flexible pressure member, and a stationary moistening medium, consisting of a flat body of absorbent material bent upwardly into a curved surface, interposed between the fixed rigid pressure member and the fixed flexible pressure member, and means for supporting the fixed rigid pressure .member, the stationary moistening medium, and the fixed flexible pressure member in the said relative positions.

2. In an envelope sealing machine, moistening mechanism comprising, in combination, a fixed rigid pressure member, a fixed flexible pressure member, and a stationary moistening medium, consisting of a flat body of absorbent material bent upwardly into a curved surface, so interposed between the fixed rigid pressure member and the fixed flexible pressure member that the pressure exerting surfaces of the fixed rigid pressure member and the fixed flexible pressure member and the pressure exerting surface of the stationary moistening medium lie on opposite sides of a horizontally disposed plane intersecting the fixed rigid pressure member, the stationary moistening medium, and the fixed flexible pressure-member, and means for supporting the fixed rigid pressure member, the stationary moistening medium, and the fixed flexible pressure member in the said relative positions.

3. In an envelope sealing machine, moistening mechanism comprising, in combination, a fixed rigid pressure member, a fixed flexible pressure member, and a stationary moistening medium, consisting of a fiat body of absorbent material bent upwardly into a curved surface, so interposed between the fixed rigid pressure member and the fixed flexible pressure member as to engage in slidable frictional engagement, under pressure, the flaps of envelopes inserted between the fixed pressure members and the stationary moistening medium, and means for supporting the fixed rigid pressure member, the stationary moistening medium, and the fixed flexible pressure member in the said relative positions.

ELMER E. GRAY. 

